1College of Resources and Environment, Graduate University of Chinese Academy of Sciences, Beijing 100049, China
2State Key Laboratory of Cryospheric Sciences, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China
3Institute of Climate System, Chinese Academy of Meteorological Sciences, Beijing 100081, China
4NASA Goddard Institute for Space Studies and Columbia Earth Institute, Columbia University, New York, NY 10025, USA
5State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
6National Climate Center, China Meteorological Administration, Beijing 100081, China
Abstract. In this study, we focus on the latest NASA GISS composition-climate model to evaluate its performance in simulating the spatial distribution of snow BC (sBC) in the Arctic relative to present observations. The radiative forcing due to BC deposition to the Arctic snow and sea ice is also estimated. Two sets of model simulations have been done in the analysis, where meteorology is linearly relaxed towards National Centers for Environmental Prediction (NCEP) and towards NASA Modern Era Reanalysis for Research and Applications (MERRA) reanalyses. Results indicate that both of the modeled sBC are in good agreement with present-day observations in and around the Arctic Ocean, except for underestimation at a few sites in the Russian Arctic. The overall ratio of observed to modeled sBC is 1.1. The result from the NCEP run is slightly better than that from the MERRA run. This suggests that the latest GISS-E2-PUCCINI model does not have significant biases in its simulated spatial distribution of BC deposition to the Arctic, and underestimation of biomass burning emissions in Northern Eurasia is preliminarily considered to be the main cause of the simulation biases in the Russian Arctic. The combination of observations and modeling provides a comprehensive distribution of sBC over the Arctic. On the basis of this distribution, we estimate the decrease in snow and sea ice albedo and the resulting radiative forcing. It is concluded that the averaged decrease in snow and sea ice albedo in and around the Arctic Ocean (66–90° N) due to BC deposition is 0.4–0.6% from spring 2007–2009, leading to regional surface radiative forcings of 0.7 W m−2, 1.1 W m−2 and 1.0 W m−2, respectively in spring 2007, 2008 and 2009.